Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
816 PM EDT Thursday Sep 18 2014
high pressure will build across the region tonight into Saturday. A
cold front will cross the region later Sunday into Monday.
Near term /through Friday/...
high pressure will build east toward the forecast area overnight.
Any remaining clouds will dissipate early tonight...leaving clear
skies overnight. Clear skies and decreasing winds will allow
favorable conditions for radiational cooling overnight. Expect
widespread frost to develop overnight across northern/central
portions of the forecast area...with areas of frost across
interior downeast areas. Have included southern Piscataquis and
central Penobscot counties in the freeze warning with this update.
A frost advisory remains in effect for interior downeast areas.
Overnight low temperatures will range from the middle 20s to around 30
north...with around 30 to the lower 30s across central portions of
the forecast area...lower to middle 30s interior downeast with upper
30s along the downeast coast. In addition to adjusting
headlines...have updated to adjust for current conditions along
with expected overnight temperatures.
a crisp fall day is on tap for tomorrow. We'll see lots of
sunshine but temperatures will definitely be on the cool side.
Highs will range from the lower 50s in the north to the middle and
upper 50s south.
Short term /Friday night through Sunday/...
high pressure center is expected to move into the Gulf of Maine
and this will initiate return flow across the region as we go into
Friday night. This return flow will keep lows generally in the
upper 30s to lower 40s across the forecast area Friday night. Clouds will be
on the increase across the west Friday night and spread south and
east as we go into Saturday in association with approaching cold
front. Right now shower chances look to hold off for much of
Saturday with only slight to chance probability of precipitation moving into western
portions of the forecast area later Saturday afternoon. High temperatures
Saturday are expected to generally stay in the lower 60s. Then
shower chances slowly advance mainly across the northern portions
of the region Saturday night. Chance showers will continue to
slowly spread south into into much of the region as cold front
continues to slowly move east. There are some differences in the
guidance in terms of speed of the front with 00z European model (ecmwf) being just
a bit more progressive. That said will lean toward a more
consensus approach which will bring some likely probability of precipitation across the
far northwest and keep chance probability of precipitation across much of the region Sunday
afternoon. Ahead of front expect high temperatures to get into the
upper 60s to lower 70s.
Long term /Sunday night through Thursday/...
we begin the period with frontal boundary approaching the region
from the west. The European model (ecmwf) continues to be most progressive guidance
during the period with previous runs GFS and Canadian wanting to
develop a secondary low that rides up the coast. The respective
12z runs of both the GFS and Canadian now keep this secondary
development further south. Right now with a bit more uncertainty
existing will stick close to model consensus. Guidance does
generally agree that the boundary will move mostly south of the
region as we move into later Monday afternoon. Mostly cloudy
conditions will persist into the Monday night with west to northwest flow
behind front. Guidance is good agreement with another weaker
shortwave approaching the region later Tuesday into Tuesday night.
Given little moisture in place this will be a light event chance
to mainly slight chance probability of precipitation. Surface high is expected to build
east as we go into Wednesday and Thursday bringing mostly clear to
mostly sunny conditions across the region. Sunday expect above
normal temperatures then temperatures go back to near normal conditions rest of
Aviation /00z Friday through Tuesday/...
near term: VFR conditions will occur across the region overnight
Short term: most areas stay VFR through much of the period. Sites
across the north particularly as we get into later Sunday into
early Monday could see MVFR in heavier showers. Improving conditions
as we go into Tuesday.
near term: a Small Craft Advisory remains in effect for much of
the waters...with the exception of the intracoastal
waters...overnight into Friday morning where wind gusts up to 25 knots
will develop later tonight then persist into Friday morning.
Short term: no headlines during this period at this time. However
persistent southerly flow is expected to bring seas up to near 5
feet on Saturday night in outer waters.
ME...freeze warning from 1 am to 8 am EDT Friday for mez005-006-010-
Frost advisory from 1 am to 8 am EDT Friday for mez015>017.
Marine...Small Craft Advisory until 10 am EDT Friday for anz050-051.